In fabricating a system-in-package (SiP), one of the necessary processes is the application of electromagnetic interference (EMI) shielding, which is required to minimize EMI between the components in the package, and with other devices.
A conventional process for EMI shielding for a system-in package with a small form factor is a two-step process, wherein a through-mold laser trench drilling process is followed by conductive paste dispense or printing to form an internal EMI shielding in between components in the SiP. Commonly a physical vapor deposition process by sputtering of copper is then used to produce an external EMI shielding for the entire SiP.
This conventional EMI shielding method, although generally effective in producing an EMI shield in a small form factor, is complex and expensive due to the two-step processing for EMI shielding and due to the high equipment cost and low deposition rate of the sputtering process.